This issue consists of a special report on the Japanese concept of "characters." Since the beginning of this millennium, there has been active discussion of "characters," with a steady stream of publications on the topic in not only linguistics and communication theory, but also in the fields of manga studies, modern thought, psychoanalysis, sociology, literary theory, socio-cultural theory, and media studies. But the content of the "characters" being studied is not uniform, and includes a uniquely Japanese concept of "character" that cannot be translated by the English word "character." Sometimes the word is even spelled "Kyara" in recognition of the fact that this is a concept specific to Japan.In this issue, the authors address the Japanese-born "characters" that are directly related to language and communication. Naturally, there are differences in terms of subtle nuance among the authors, but there are no large discrepancies in their use of the everyday word "character," which has been built up in the course of daily life by general Japanese speakers, especially young people. This everyday word "character" signifies an image of humanity that is not incompatible with the traditional view that "barring some extraordinary circumstance, such as the disintegration of personality, people do not change depending on the situation. What changes is style; people change their style in response to the situation." As it is taboo to overtly violate this traditional view of humanity, nobody will openly admit to "changing depending on the situation." However, on anonymous electronic bulletin boards, young people are secretly coming out about the fact that they have "different characters for school and for their part-time jobs." These are the main kind of "characters" discussed here. This issue gathers together articles that introduce knowledge obtained in Japan regarding "characters," and clarify their relationship with the Japanese language, Japanese communication, and education in both these areas. It also contains articles discussing the potential contributions of "characters" to general research in linguistics and communication, beyond the Japanese-speaking community.Toshiyuki Sadanobu presents one method of organizing the various concepts in Japan that fall under the technical term "character," shows how one type (which was, as mentioned above, created mainly by the young generation) pushes the limits of the traditional view of humanity and the speech-act view, which assumes intention, and discusses the relationship between characters and Japanese communication.Kenji Tomosada describes cases found in regional dialects that parallel Sadanobu's observations on "chara-joshi" in common Japanese. Just as the common Japanese speaker expresses his/her identity by means of "chara-joshi," so too the speaker of Japanese dialects embodies his/her identity with the sentential-final particles wa, wai, and bai. "Chara-joshi" and wa, wai, and bai also look alike in that they occur at the end of a sentence, even after the attitudinal particles.Satoshi Kinsui and Hiroko Yamakido supplement some of the deficiencies of the definition of role language in Kinsui (2003), and redefine role language as knowledge of "a manner of speaking that binds together a social or cultural group" possessed by "the majority of constituents in a linguistic community."Fumiaki Senuma investigates communities of young people in modern Japanese society and developments in his research since then. Among the young generation, individuals are sometimes assigned a specific kyara by others in their peer group, regardless of that individual's intentions.Yukiko Shukuri reports on the status of Japanese language teaching materials related to role language and characters, and describes her research project activities on role language and character in Novosibirsk, Russia.We hope that this issue will stimulate discussions on "character theory" in the worldwide context of Japanese language and culture research.